I have a male platy tank with a few males and fry of different stages.
The trouble I have is with the two four month old males, they are brothers from the same batch. The issue is that one hounds the other one so badly, he follows him, blocks him, displays at him, nips hims and the other one rams and flicks him back, but it’s relentless! And actually uncomfortable to watch!
The one that’s being bothered is now like 2 or 3 times the size of the other one as the other one spends his time and energy stalking his brother, while his brother eats and grazes all day.
The hounded one does seem stressed and keeps getting a bloated stomach (not dropsy, no pineconing) the bloat goes down if I don’t feed them, the back again.
Thinking it might be stress.
I have tried putting the pest male in breaded net for an hour but that had no effect other than stress, so won’t be doing that again.
Any advice on this behaviour would be great otherwise might need to put in a tank divider.
I have a 65ltr female tank but rally don’t want any males in there as just trying to get on top of the population.
Water stats are good Ammonia 0 Nitrite 0 Nitrate 5 PH 7.2 KH & GH are always low so adding in coral sand
60ltr tank Fluval U2 Plenn and plax small world filter Ocean rock Couple of plants Coconut half for shrimp
Stock 1 full grown male 2 five month old males - one hounds the other 1 four month old 6 two month old fry - all free swim around the tank 2 one month only fry - swim in tank 4 Amano Shrimp
Epsom salt isn't likely to help as this sounds to be food-related rather than an osmotic stress issue (it wouldn't go up and down if he was taking on water). Try giving them some de-skinned squished peas or some live daphnia which will help digestion.